#include<bits/stdc++.h>
using namespace std;
int main(void){
    double n;
    cin >> n;
    if(n<0){
        n = -n;
        printf("-%.6f",pow(n,1.0/3));
    }
    else{    
        printf("%.6f",pow(n,1.0/3));
    }
    return 0;
}